GUIUtils.cs

using UnityEngine;
using System.Collections;
using Holoville.HOTween;

public class GUIUtils : MonoBehaviour
{
    public UISprite transition;

	void Awake()
	{
		Instance = this;
	}

	public static Tweener Transition(Color transitionColor)
	{
		if (Instance == null)
		{
			ThrowNullInstanceException();
			return null;
		}
		
		TweenParms parms = new TweenParms()
				.Prop("color", transitionColor)
				.UpdateType(UpdateType.TimeScaleIndependentUpdate);
	
		Tweener transitionTween = HOTween.To(Instance.transition, 1f, parms);
		
		return transitionTween;
	}
}